1. Technical Field
The present disclosure relates to vehicle body manufacturing apparatuses that weld one work of a vehicle body to another work by spot welding to pre-assemble the vehicle body.
2. Related Art
There have been proposed and put into practical use various techniques for pre-assembling a vehicle body by spot welding plural works included in the vehicle body with the works positioned. For instance, Japanese Unexamined Patent Application Publication (JP-A) No. 2-14984 discloses a technique for assembling a vehicle body, in which by the operation of each of positioning robots in a main body assembling apparatus, a work receiving jig and a work receiving surface are disposed at predetermined positions and works are positioned relative to each other, then these works are fixed by the operation of each of clamping mechanisms, and interposed and fixed between the work receiving electrode and the electrode tip of a welding robot to be spot welded.
However, when clamping, positioning, fixing of each work by a positioning robot and clamping, positioning, fixing of each work by a welding robot are independently performed as in the above-described technique for assembling a vehicle body disclosed in JP-A No. 2-14984, the clamping, positioning, fixing of each work may not be maintained with high precision in a comprehensive manner. In addition to clamping and fixing function of the welding robot, clamping mechanism of the positioning robot has to be provided, and thus many pieces of equipment having redundant functions have to be provided in production of vehicles. Furthermore, a working time for installing those pieces of equipment is needed, and also working space is reduced due to the pieces of equipment, thereby causing working efficiency to be reduced.